The wire reinforcement is typically placed within wooden or metallic forms so as to be spaced at particular distances from the surfaces of the reinforced concrete. For this purpose, there exist spacing meshes which typically comprise small diameter wires that are bent in particular forms so as to be placeable as spacers. Such spacers are situated with their ends on the wooden or metallic form, and thus, after the hardening of the concrete, their ends remain in contact with the environment at the hardened cement's surface. At such locations of contact with the environment, the spacer steel corrodes. As a result of the corrosion progressing to the interior of the reinforced concrete, the steel expands and crumbles the concrete.
In previous attempt to avoid the onset of metal corrosion, the ends of the spacer wires were dipped into resins or plastic, typically in liquid form at high temperature, and were subsequently cooled by air flow that may include forced air. This technique is disadvantageous with respect to complexities of the liquid phase of the cover material, as well as with respect to the time for cooling and solidification of the cover material.
Another technique is the placement of prefabricated plastic covers on the wire ends by mechanisms. According to such state-of-art practices, a significant number of covers fall during handling of the spacer meshes, during transfer, during placement, and during casting of the cement; and thus, the possibility for corrosion remains.